Rotatable swing arm stabilizer assembly for folding wheelchairs

Abstract

A swing arm assembly for a foldable wheelchair consisting of a camber tube and adapters is disclosed. The adapters mount to the frame of the wheelchair and receive the ends of the camber tube. One end of the camber tube is pinned into an adapter such that it pivots. The other end is pinned in an adapter using a quick release pin. The camber tube improves the stability of the foldable wheelchair. When desired to fold the wheelchair, the quick release pin is removed and the camber tube is rotated approximately 90 degrees, thereby allowing the wheelchair to fold. The adapters may be mounted to the wheelchair frame or to stub axles if used. The swing arm assembly adds substantial stiffness and stability to a folding wheelchair.

We claim: 
     
       1. A folding wheelchair with a rotatable swing arm assembly, comprising:
 a folding wheelchair; 
 a camber tube having a diameter, a length, a first end, and a second end, wherein the camber tube is sized to receive a clamshell bracket attachment mechanism of an external motor unit; 
 a first camber tube adapter having a pin hole and fixedly attached to the camber tube's first end; 
 a second camber tube adapter having a pin hole and fixedly attached to the camber tube's second end; 
 a first pin sized to fit into the first camber tube adapter's pin hole; 
 a second pin sized to fit into the second camber tube adapter's pin hole; 
 a first wheelchair adapter attached to a first frame member of the folding wheelchair, the wheelchair having a first main wheel and a second main wheel, the wheelchair configured to fold such that the first main wheel and the second main wheel come within close proximity to each other when folded, the first wheelchair adapter configured to receive the first camber tube adapter such that the rotatable swing arm assembly rotates with respect to the wheelchair; and 
 a second wheelchair adapter attached to a second frame member of the folding wheelchair, the second wheelchair adapter having a pin hole and configured to receive the second camber tube adapter, wherein the second camber tube adapter's pin hole aligns with the second wheelchair adapter's pin hole thereby maintaining a fixed distance between the wheelchair's first main wheel and second main wheel. 
 
     
     
       2. The folding wheelchair with a rotatable swing arm assembly of  claim 1 , wherein the camber tube is made from carbon fiber. 
     
     
       3. The folding wheelchair with a rotatable swing arm assembly of  claim 1 , wherein the rotatable swing arm assembly stays connected to the first wheelchair adapter when the folding wheelchair is folded. 
     
     
       4. The folding wheelchair with a rotatable swing arm assembly of  claim 1 , wherein the first camber tube adapter and the second camber tube adapter are an integral part of the camber tube. 
     
     
       5. The folding wheelchair with a rotatable swing arm assembly of  claim 1 , wherein the second wheelchair adapter further comprises a first adapter arm having a first pin hole sized to receive the first pin and a second adapter arm having a second pin hole sized to receive the second pin, the second pin hole coaxial with the first pin hole, wherein the first adapter arm and the second adapter arm are spaced apart thereby forming a slot. 
     
     
       6. The folding wheelchair with a rotatable swing arm assembly of  claim 5 , wherein the slot is sized to receive a portion of the second camber tube adapter such that the second camber tube's pin hole coaxially aligns with the first and second adapter arm's respective first and second pin holes. 
     
     
       7. The folding wheelchair with a rotatable swing arm assembly of  claim 1 , wherein the wheelchair further comprises stub axles, and wherein the stub axles are configured to receive the first wheelchair adapter and the second wheelchair adapter. 
     
     
       8. The folding wheelchair with a rotatable swing arm assembly of  claim 1 , wherein the wheelchair further comprises stub axles having the first wheelchair adapter and the second wheelchair adapter integrally formed into the stub axles. 
     
     
       9. The folding wheelchair with a rotatable swing arm assembly of  claim 1 , wherein the camber tube comprises a first portion and a second portion, wherein the first portion and the second portion are threaded such that the first portion engages the second portion using the threads thereby allowing for adjustment of the camber tube's length. 
     
     
       10. The folding wheelchair with a rotatable swing arm assembly of  claim 1 , wherein the first pin and the second pin are a bolt, a cotter pin, or a quick release ‘T’ handle pin.